A robot cleaner is a device which suctions foreign substances, such as dust, from a floor surface to perform cleaning by itself while traveling through a cleaning area without a user's operation. The robot cleaner detects a distance to an obstacle, such as a piece of furniture, an office supply, or a wall installed in the cleaning area, using a distance sensor and selectively drives a left or right wheel motor of the robot cleaner to change a direction thereof and clean the cleaning area by itself.
Generally, a robot cleaner includes a suction port at a bottom surface thereof and suctions foreign substances on a floor surface through the suction port. A main brush is rotatably provided at a side of the suction port to pick up dust on the floor surface. Accordingly, the robot cleaner can easily suction foreign substances located under a main body thereof, but there is a problem in that the robot cleaner suctions foreign substances located outside the main body.
A robot cleaner is provided in various shapes. Generally, since a robot cleaner having a cylindrical shape easily avoids an external obstacle while traveling, traveling performance of the robot cleaner is excellent. However, a poorly cleaned area, such as a corner of a wall, can occur due to the cylindrical shape. On the other hand, a robot cleaner having a polygonal shape, such as a tetragonal shape, can minimize a poorly cleaned area such as a corner of a wall. However, due to the polygonal shape being obstructed by external obstacles, traveling performance of the polygonal robot cleaner can be lower than that of the cylindrical robot cleaner while traveling.